Methods for dentistry using compositions comprising an oil

ABSTRACT

The present invention provides non-metallic compositions that are useful to repair, restore, adhere to, or protect, the surface of a tooth and that harden in the moutn to form substantially permanent features therein or to adhere fixtures to the surface of a tooth in a substantially permanent manner. The compositions comprise an amount of an essential oil effective to alter the sensory properties, i.e. the taste, a smell, of the composition and that desirably imparts a pleasant taste and/or order. The essential oil further advantageously provides the composition, once hardened in the mouth, with a surface more hydrophobic than a corresponding conventional composition, thereby inhibiting the deposition or formation of bacterial plaque. Also provided are a method of using the compositions to repair or seal hard dental tissue, as well as a method to adhere one or more dental or orthodontic fixtures to hard dental tissue.

REFERRENCE TO RELATED APPLICATION

[0001] Reference is hereby made to commonly-assigned Application Ser.No. _________ entitled FLAVORED TOOTH CONDITIONING COMPOSITIONS ANDMETHODS FOR USING THE COMPOSITIONS TO CONDITION A TOOTH SURFACE filed oneven date herewith.

FIELD OF THE INVENTION

[0002] This invention relates to compositions that harden in the mouthto repair, restore, adhere to, or protect, the surface of a tooth. Inparticular, the present invention relates to non-metallic compositionsthat comprise an amount of an essential oil and that are intended to besubstantially permanent once hardened within the mouth. The inclusion ofthe essential oil can provide many advantageous properties to thecompositions, e.g., a more pleasant flavor and/or odor; hydrophobicity,which in turn renders the hardened compositions with a greater plaqueresistance; and enhanced processing and handling characteristics. Theinvention also relates to methods for repairing, restoring, adhering to,or protecting a tooth by using the compositions as sealants,restoratives, composites and adhesives.

BACKGROUND OF THE INVENTION

[0003] Adhesion procedures are utilized in many forms of dentaltreatment. For example, adhesives are used in orthodontic treatment toadhere metal or ceramic brackets directly to tooth enamel. For theprevention of tooth decay, resin-based materials, called pit and fissuresealants, are often bonded to enamel to provide a coating that protectsthe enamel from decay. Additionally, adhesives may be used to secure theadhesion of a tooth filling material at its margins with enamel anddentin, in order to reduce or eliminate the penetration of microbialagents across these margins. Adhesive materials may also be used torestore teeth in a number of ways. In particular, when a minorrestoration or repair is required, e.g., as when a tooth is missing anincisal edge, new material can be bonded to the surface of the tooth toreplace the tooth material that has been lost rather than removingextensive additional tooth material in order to place a crown. Adhesivematerials are also used in situations where a greater amount of oralrehabilitation is required, as in the cementing of inlays, crowns andbridges. Adhesive technology is also used in aesthetic dentistry, whereveneers can be cemented on to the enamel facing of teeth to mask defectsor areas of discoloration.

[0004] It can thus be seen that adhesion procedures are central to thepractice of dentistry. Advantageously, in recent years, adhesivematerials have been developed that are not only more durable thanadhesive materials of years past, but that are also capable of formingsubstantially permanent bonds with and between the materials to whichthey bond. Thus, when utilized in their respective applications, thesematerials are capable of performing their desired function for longperiods of time, i.e., years or even a lifetime, thus potentiallyreducing the frequency of required dental treatment.

[0005] Although these materials are widely used in contemporary dentalpractice, and are generally extremely effective in each of theirrespective applications, there still exist areas in which improvementsto adhesive materials would be desirable, i.e., that would result in thefurther enhancement or optimization of the properties of thesematerials. For example, many adhesive materials have a bitter taste, andleave an unpleasant after-taste in the mouth, which may be particularlyproblematic when the patient being treated is a child. Additionally,some of these materials, when hardened, can attract and/or contribute tothe formation of bacterial plaque on the surfaces thereof due to thefact that these surfaces are generally not sufficiently hydrophobic toprevent such plaque accumulation. Finally, some of the aforementionedmaterials are difficult to handle or to mold into the desired shape andplacement in the mouth, lengthening the time required to perform certainprocedures utilizing these materials.

[0006] It would thus be desirable to provide materials with either nosubstantial flavor and/or odor, or more preferably, with a pleasantflavor and/or odor. It would further be desirable to provide materialswhich inhibit the ability of bacterial plaque to form on these materialswhen hardened in the mouth. Finally, such materials would desirably beeasily and conveniently shaped and placed within the mouth, so that theamount of time required to do so is desirably reduced.

SUMMARY OF THE INVENTION

[0007] The present invention is drawn to compositions that harden in themouth to repair, restore, adhere to, or protect, the surface of a tooth.In particular, the present invention relates to non-metalliccompositions that comprise an amount of an essential oil and that areintended to be substantially permanent once hardened within the mouth.The inclusion of the essential oil can provide many advantageousproperties to the compositions, e.g., a more pleasant flavor and/orodor; hydrophobicity, which in turn renders the compositions whenhardened with a greater plaque resistance; and enhanced processing andhandling characteristics.

[0008] Thus, in one aspect, the present invention provides non-metalliccompositions for use in dentistry comprising an essential oil in anamount effective to alter one or more of the sensory properties of thenon-metallic composition and wherein the non-metallic compositionhardens in the mouth to form a substantially permanent feature withinthe mouth.

[0009] In another aspect, the present invention provides non-metalliccomposition for use in dentistry comprising an essential oil wherein thenon-metallic composition hardens in the mouth to form a substantiallypermanent feature and wherein the essential oil is present in an amounteffective to provide the feature with a substantially hydrophobicsurface.

[0010] Because the essential oil imparts a more hydrophobic nature tothe surface of the non-metallic compositions when hardened, the surfaceof the hardened compositions are less susceptible to the formation ofbacterial plaque. Thus, the compositions of the present invention findparticular utility when used in methods to repair or seal a toothsurface. As a result, in another aspect, the present invention providesa method for repairing or sealing hard dental tissue comprising applyingto said tissue a non-metallic composition comprising an essential oil;and causing said composition to harden on said tissue. Once hardened,the composition is intended to be a substantially permanent feature onsaid tissue.

[0011] In addition to the advantageous properties afforded tocompositions by virtue of the inclusion of the essential oil, theessential oils also advantageously do not substantially interfere withthe ability of the inventive compositions to harden and to formsubstantially permanent bonds with a tooth surface, or between a toothsurface and an additional dental material, e.g., such as a crown orbridge. This is a surprising and unexpected result in as muchconventional dental knowledge teaches that some oils can interfere withthe ability of polymerizing materials to harden or cure, and also thatin general, oils interfere with the adhesive bonding of materials totooth substance.

[0012] Thus, in another aspect, the present invention provides a methodof adhering a dental or orthodontic fixture to hard dental tissuecomprising applying to said tissue a non-metallic composition comprisingan essential oil; placing the dental or orthodontic fixture in adhesivecontact with the composition; and causing the composition to harden onsaid tissue to adhere the fixture to the dental tissue in a manner so asto render the fixture a substantially permanent feature on the tissue.

[0013] As used herein, the phrase “non-metallic composition” is meant toindicate tooth-colored compositions, i.e., non-amalgam basedcompositions, useful to repair, restore, adhere to, or protect, thesurface of a tooth. Such compositions are typically based upon polymer,compomer or ionomer systems and although the term “non-metallic” is usedto further clarify they types of materials contemplated to be useful inthe compositions of the present invention, this term is not meant topreclude the compositions from comprising amounts of metals. Forexample, certain cements derived from glass-ionomers can contain amountsof metals, such as silver, in amounts that although not insignificant,do not interfere or participate in the hardening reaction and that donot result in the hardened materials having a metallic appearance.

[0014] Also, as used herein, the phrase “substantially permanent” as itis used pertaining to the bond between the tooth (either enamel ordentin) and an composition according to the present invention, or to thebond provided by the composition between a tooth and another dentalmaterial, e.g., a crown, is meant to indicate a bond that issufficiently strong and secure, so that the composition or applieddental material will be a substantially permanent feature within themouth, i.e., that at least at the time that the composition and/ordental material is applied, the material is intended to remain adheredto the tooth structure indefinitely. Thus, the phrase “substantiallypermanent” does not exclude dental materials that, due to extenuatingcircumstances unrelated to the initial integrity of the bond between thematerial and the tooth, fail prematurely. Generally speaking, a bondstrength of at least about 5 MPa, and preferably from about 15 MPa toabout 35 NIPa is sufficiently strong so as to render dental materialsadhered to tooth structure with this bond strength “substantiallypermanent.” Of course, those of ordinary skill in the art readilyrecognize that bond strengths indicative of permanence can varydependent upon the material being bonded, the tooth structure beingbonded to, and furthermore, that measured bond strengths are dependentupon the method of testing and the history of the extracted teeth usedfor the testing. Bond strength may be measured, for example, asdescribed below in connection with Examples 7 and 8. See also, e.g.,William J. O'Brien, PhD, “Dental Materials and Their Selection,” 2 ^(nd)ed., p. 332 (1997). It should be noted that higher bond strengths can beobtained using micro-testing methods such as those disclosed in Sano etal., “Relationship between surface area for adhesion and tensile bondstrength-Evaluation of a micro-tensile bond test.” Dent Mater 10:236,July, 1994.

[0015] Additionally, the compositions in accordance with the presentinvention advantageously include an amount of an essential oilsufficient to alter one or more of the sensory properties, i.e., tasteor smell, of the compositions. That is, the essential oil may simply actto ameliorate and otherwise unpleasant taste, or desirably, may impart amore pleasing flavor and/or odor to the composition.

[0016] Finally, as used herein, the term “hydrophobic” or“hydrophobicity” as it relates to a surface of a composition inaccordance with the present invention once it has hardened within themouth, is meant to indicate that the surface is more hydrophobic thanthe surface of a hardened analogous composition that does not comprisean amount of an essential oil. The hydrophobicity, or wettability, of asurface may be measure in a number of ways well known to those ofordinary skill in the art. For example, one method of measuring thehydrophobicity is by use of a dynamic contact angle analyzer, which isdescribed further in connection with Example 9, hereinbelow.

[0017] Unless otherwise indicated, as used herein, all references topercentages are percentages by weight of the composition.

DETAILED DESCRIPTION OF THE DRAWINGS

[0018] The embodiments of the present invention described below are notintended to be exhaustive or to limit the invention to the precise formsdisclosed in the following detailed description. Rather the embodimentsare chosen and described so that others skilled in the art mayappreciate and understand the principles and practices of the presentinvention.

[0019] The present invention provides non-metallic compositions for usein dentistry that comprise one or more essential oils. The inclusion ofone or more essential oils in the otherwise conventional compositionsprovides these compositions with many advantageous properties. First ofall, the essential oil(s) are capable of either ameliorating theunpleasant flavor, or imparting a pleasant flavor to, conventionalcompositions that otherwise would have a bitter and potentiallyunpleasant taste and/or odor. Additionally, the inclusion of anessential oil in conventional compositions is capable of rendering thesurface of such compositions, when hardened in the mouth, with a morehydrophobic surface than the same composition would have it not for theinclusion of the oil. The fact that the inclusion of one or moreessential oils in conventional compositions provides the aforementionedbenefits is extremely advantageous when the inventive compositions areutilized in dental practice.

[0020] Furthermore, not only is the inclusion of such oils not otherwisedetrimental to the properties of these compositions, i.e., does notsubstantially interfere with the ability of the composition to harden toform a substantially permanent feature within the mouth, but theessential oils may actually improve the handleability of thesecompositions. That is, while many compositions are difficult to shape orplace in the mouth in some circumstances due to their putty-likeconsistency, the compositions in accordance with the present inventionare provided with a more fluid consistency, which renders them easier toplace.

[0021] The inclusion of oils in these types of compositions to providethe aforementioned benefits has not previously been considered a viableoption to provide such benefits due to the fact that oils havepreviously been thought to interfere with the ability of thecompositions to form substantially permanent bonds to a tooth surface orwith an additional dental material. However, it has now beensurprisingly discovered that the oils suitable for use in the presentinvention can be easily and conveniently incorporated into conventionalnon-metallic compositions to provide these benefits, withoutconcurrently detrimentally affecting the ability of the compositionsbond to a tooth surface or to bond a tooth surface to additional dentalmaterials. In particular, it has now been found that certain oils do notinterfere with free radical polymerization and/or acid-base reactions inthe amounts used, and as a result, these oils can be utilized inconventional compositions to provide the aforementioned benefits.

[0022] The oils useful in the present invention are thus those oilswhich are capable of altering the sensory properties of conventionalmaterials and/or providing the materials, when hardened in the mouth,with a more hydrophobic surface than the hardened surface of a materialnot comprising an essential oil, without detrimentally affecting theability of the composition to form permanent bonds with the toothsurface or other dental materials, i.e., that do not interfere with freeradical polymerization, and which are orally non-toxic. Generallyspeaking, these qualities are embodied by “essential” oils, i.e., oilswhich are derived from plant sources or animal sources Examples of suchoils include, but are not limited to, soybean oil, safflower oil, sesameoil, olive oil, sunflower oil, canola oil, walnut oil, peanut oil,orange oil, eucalyptus oil, cod liver oil, castor oil, combinationsthereof, and the like. Such oils are readily commercially available froma variety of sources as will be readily appreciated by one of ordinaryskill in the art. Furthermore, inasmuch as these oils are consumablefood items in reasonable quantities, oral toxicity is generally not aconcern.

[0023] As used herein the phrase “non-metallic composition” is meant toindicate a tooth colored material that is used in the mouth to repair,replace or otherwise complement the surface of a tooth, whether appliedto enamel or dentin, and that once placed in the mouth and caused toharden, forms a substantially permanent feature. Such materials include,for example, sealants, adhesives, composites, restoratives, and thelike. Although there are many different types of each of thesematerials, e.g., resin composites, compomers, glass-ionomers andresin-modified glass-ionomers, the type of material into which the oilis to be incorporated is not particularly restricted, and in fact. it isbelieved that the oil may be mixed into many if not all types of theaforementioned materials and provide the advantages disclosed herein.

[0024] Resins and resin composites are materials that harden by apolymerization reaction mechanism. Generally, the polymerizationreaction is a free radical addition polymerization, activated either bychemicals, or more usually, by visible light. Resins and resincomposites may optionally contain inert inorganic fillers (silica,barium glass, zirconialsilica glass are some examples) to modifyproperties. These types of materials adhere micromechanically to toothenamel following acid etching and bond to dentin via application of anacid conditioner followed by a primer and/or adhesive, after whichapplication a combination of micromechanical and interdiffusion bondingoccurs. As is well known to those of ordinary skill in the art, manydifferent types of resins and resin composites are commerciallyavailable, and typically vary in the type, concentration and propertiesof the filler. Representative examples of commercially available resincomposites include, but are not limited to, Revolution (KerrCorporation, Orange, CA); Silux (3M, St Paul, Minn.); HRV Herculite(Kerr Corporation, Orange CA); Restorative Z100 (3M, St Paul, Minn.);and Alert (Pentron Inc, Wallingford, Conn.).

[0025] Glass-ionomers, sometimes referred to as polyalkenoate cements,set and/or harden via an acid-base reaction. wherein an acidic polymeror copolymer aqueous solution reacts with an ion-leachable glass. Forexample, poly(acrylic acid) and related copolymers-referred referred tohere as PAA-can react with a fluoroaluminosilicate glass (FAS) to give aset product consisting of a core of some unreacted FAS surrounded by theacid-base reaction products. Glass-ionomers, when set, contain anaqueous phase, and also fluoride ions from the chemical breakdown of theFAS. These materials are capable of chemical adhesion to a toothsubstance, because of ionic attraction between PAA anions and thecalcium of enamel and dentin. Glass-ionomers are well-known compositionsto those of ordinary skill in the art and are readily commerciallyavailable. One representative example of a commercially availableglass-ionomer includes, but is not limited to, Ketac-Cem Radiopaque(Espe America, Inc, Norristown PA).

[0026] Resin-modified glass-ionomers are often used in situationswherein properties intermediate between those of resins andglass-ionomers are desired. Resin-modified glass-ionomers set and hardenvia a combination of an acid-base reaction and a polymerizationreaction, which may be activated chemically and/or by the application ofvisible light. These materials, like glass-ionomers, contain an aqueousphase when set, which ensures that fluoride ions are present that canthen leach from the hardened material over time. Resin-modifiedglass-ionomers are well-known compositions to those of ordinary skill inthe art and are readily commercially available. One representativeexample of a commercially available resin-modified glass-ionomersincludes, but is not limited to, GC Fuji II LC Improved (GC America Inc,Alsip, Ill).

[0027] Compomers are also advantageously used in situations whereinproperties intermediate between those achievable with resins andglass-ionomers are desired. Compomers are polyacid-modified resincomposites that set and/or harden via a polymerization mechanism.Compomers are well-known compositions to those of ordinary skill in theart and are readily commercially available. One illustrative example ofa commercially available compomer includes, but is not limited to,Compoglass® (Ivoclar North America Inc, Amherst, N.Y.).

[0028] The non-metallic compositions of the present invention mayreadily and conveniently be prepared at a point of use by one ofordinary skill in the art by simply combining the desired essential oilwith any desired conventional non-metallic composition. Such combiningmay take place immediately prior to the use of the composition, oralternatively, the oil may be combined with the conventional compositionand then stored until the use thereof is desired. If the composition isto be stored for a period of time, the conditions of storage are notsubstantially impacted by the inclusion of the essential oil, and thuscompositions in accordance with the present invention may be stored inthe manner appropriate for the conventional composition.

[0029] The oil is desirably included in the non-metallic composition inan amount that is effective to alter the sensory properties of thecomposition and/or to render the surface of the composition, whenhardened, more hydrophobic than the corresponding conventionalcomposition. As a lower limit, at least enough of the oil should beincluded so that the oil is at least capable of reducing or eliminatingany other unpleasant flavors of the composition and/or rendering thesurface of the hardened composition at least marginally more hydrophobicthan its conventional counterpart. As an upper limit, not so much oilshould be included so that the effectiveness ofthe composition issubstantially-detrimentally affected. Bearing these considerations inmind, and generally speaking, the amount of oil that is thought toachieve the aforementioned objectives will likely range from about 0.1weight percent (wt%) to about 10 wt%, preferably from about 1 wt% toabout 5 wt%, more preferably from about 1.5 unit% to about 3 wt%, basedupon the weight of the conventional composition without the oil.

[0030] Of course, the particular amount of oil that is to be included inthe composition will be dependent upon the particular conventionalcomposition and oil chosen. For exemplary purposes only, and in thatembodiment of the invention wherein the conventional composition isRestorative Z100 (3M, St. Paul, Minn.) and the oil is soybean oil, theoil is desirably included in the conventional composition in an amountof from about 0.1 % to about 10% to prepare one representativenon-metallic composition in accordance with the present invention.

[0031] Although it is contemplated that any of the essential oils listedabove, or any other essential oil that does not substantially interferewith the ability of the composition to harden or cure to form asubstantially permanent feature within the mouth, will be capable insome amount of at least minimizing the unpleasant flavor of, orimparting a pleasant flavor and/or odor to, any conventionalcomposition, in some instances it may be desirable to impart a strongerflavor, or a particular flavor that is not readily available in an oilform. For example, children generally prefer sweeter and/or strongerflavors than adults and thus may prefer flavors such as cherry,strawberry, blueberry, watermelon, lemon, lime, raspberry, apple, grape,cranberry, coconut, banana, tangerine, pineapple, bubble bum, almond,hazelnut and the like, rather than spearmint or orange flavors. In theseinstances, the essential oil to be incorporated into the composition ofthe present invention may further have incorporated therein an amount ofa flavoring agent such as those previously mentioned, i.e., theessential oil may act as a carrier for other flavoring agents. Suchflavoring agents are readily commercially available as either syrups,solutions or solids, and may be incorporated into the essential oilsimply by mixing the desired flavoring agent with the essential oil.Experiments have shown that the inclusion of such a flavoring agent inthe essential oil will not have a detrimental effect on the ability ofthe composition to substantially bond another dental material to, oritself to bond with a tooth surface.

[0032] The non-metallic compositions of the present invention mayoptionally comprise other ingredients that may be used to furtherenhance the sensory and/or mechanical properties of the non-metalliccompositions. For example, it has additionally been found that certainother liquids, such as glycerol or propylene glycol, can be used ascarriers for the flavoring agents mentioned hereinabove while notsubstantially adversely affecting the properties of the compositionsinto which they are incorporated. Thus, such liquids can be used, eitheralone or in conjunction with the essential oils, to incorporateadditional flavoring agents in those embodiments of the invention wherethis is desired.

[0033] The non-metallic compositions of the present invention,comprising an essential oil, are advantageous over conventionalcompositions in that they have either a lesser unpleasant flavor and/orodor than their conventional counterparts, or may even have a pleasantflavor relative to conventional compositions. Furthermore, the presentinventive compositions, when hardened in the mouth, have a morehydrophobic surface than analogous conventional compositions.Surprisingly, utilizing an essential oil to provide these advantageousproperties to conventional compositions does not adversely affect theability of the inventive compositions to bond to a tooth surface, or tobond a tooth surface with other dental materials. As a result, thecomposition of the present invention may advantageously be used torepair, seal or alter the position of teeth (as by the adherence oforthodontic fixtures to the tooth) and thus the present inventionprovides both a method of repairing or sealing hard dental tissue, i.e.,the surface of a tooth, whether it be a dentin or enamel surface, aswell as a method of adhering a dental or orthodontic fixture to harddental tissue.

[0034] More specifically, the methods of the present invention involveapplying a non- metallic composition comprising an essential oil to thetissue to be so treated. The composition may be applied to the tissuethat is to be repaired, sealed or have a fixture adhered thereto by anyconventional method known to those of ordinary skill in the art. Inapplications wherein no further treatment is desired, i.e., where noother dental fixtures are to be placed or adhered, such as is the casein certain treatments to repair or seal the teeth, the composition issimply caused to harden on said tissue. The inclusion of the essentialoil in conventional compositions surprisingly does not substantiallyadversely affect the ability of, or the manner in which, theconventional composition hardens or cures, and thus, the presentinventive composition may be caused to harden or cure by the same methodused to cause the corresponding conventional composition to harden orcure. In applications wherein a dental or orthodontic fixture is to beadhered to the tissue, the composition is applied to the tissue to be sotreated, followed by the fixture. The composition is then caused toharden, thereby substantially permanently adhering the fixture to thetissue.

[0035] Beneficially, the bond strength that may be achieved between ahard dental tissue and the compositions of the present invention, orthat is achieved between the tissue and another dental fixture by virtueof the inventive compositions, is comparable to that that is achievablewhen a conventional composition is utilized to treat a tooth surface, asis shown in Examples 5-8, hereinbelow.

[0036] The present invention will be described below with reference tothe following representative examples, wherein bond strength wasdetermined as follows.

Example 1

[0037] The following experiment was conducted to evaluate the impact ofthe inclusion of an oil on the abilitv of conventional resin-basedcompositions to set or harden. In particular, ten percent by weight ofeach of 10 oils (soybean, canola, sesame, olive, orange, eucalyptol,almond, safflower, walnut and cod liver oil) and 5 % by weight ofethanol, propylene glycol and glycerol was added to each of three resinbased materials: Restorative Z100 (3M, St Paul, Minn.), ColteneBrilliant Dentin (Coltene/Whaledent, Mahwah, N..J.), and System 1+adhesive (Ormco, Glendora, Calif.) to prepare non-metallic compositionsin accordance with the present invention.

[0038] The compositions, along with control samples of the conventionalresin-based composites, were then irradiated with blue light ofwavelength 470-480 nm and minimum intensity 450 mW/cm² for 40 seconds(Visilux 2 curing light, 3M, St Paul, Minn.). Each inventive compositionquickly hardened to form a set mass, similar to the conventionalresin-based composites. It was observed that the inclusion of the oilsresulted in the inventive compositions having a smoother texturerelative to the conventional resin-based composites, thus rendering theinventive compositions easier to handle.

Example 2

[0039] The following experiment was conducted to evaluate the impact ofthe inclusion of an oil on the ability of conventional resin-modifiedglass ionomer compositions to set or harden. In particular, ten percentby weight of each of 10 oils (soybean, canola, sesame, olive, orange,eucalyptol, almond, safflower, walnut and cod liver oil) and 5 % byweight of ethanol, propylene glycol and glycerol was mixed with each oftwo resin-modified glass-ionomers (Vitremer, 3M, St Paul, Minn. and FujiII LC, GC America, Alsip, Ill.) to prepare non-metallic compositions inaccordance with the present invention.

[0040] The compositions, along with control samples of the conventionalresin-modified glass ionomers, were then irradiated with blue light ofwavelength 470-480 nm and minimum intensity 450 mW/cm² for 40 seconds(Visilux 2 curing light, 3M, St Paul, Minn.). Each inventive compositionquickly hardened to form a set mass, similar to the conventionalresin-modified glass-ionomers. This example thus shows that theinclusion of the oil does not interfere adversely with either the freeradical addition polymerization (similar to Example 1) or with the ionicacid-base reaction between the PAA and the FAS.

Example 3

[0041] This experiment was conducted to further investigate the effectof the inclusion of an oil on the acid base reaction between PAA andFAS. In particular, the ten oils listed in Examples 1 and 2, ethanol,propylene glycol and glycerol were each mixed with PAA samples having aweight average molecular weight of from about 20,000 to about 1,000,000in aqueous form. In all cases, the oil or other carrier dissolved in thePA-A thereby allowing the inference that PAA exists in ionic form in themixtures containing water. This provides a number of desirablecharacteristics. First, the ionic nature of PAA allows the acid-basereaction to occur. Also, there is an ionic nature to the mechanism ofadhesion.

Example 4

[0042] The following experiment was conducted to evaluate the impact ofthe inclusion of an oil on the ability of conventional compomercompositions to set or harden. In particular, ten percent by weight ofeach of 10 oils (soybean, canola, sesame, olive, orange, eucalyptol,almond, safflower, walnut and cod liver oil) and 5 % by weight ofethanol, propylene glycol and glycerol was mixed with F2000 compomer(3M, St Paul, Minn.) to prepare non-metallic compositions in accordancewith the present invention. These samples were irradiated as in Example1.

[0043] In all cases setting occurred in a manner indistinguishable fromthe unmodified material. Example 5

[0044] The following experiment was conducted to evaluate the impact ofthe inclusion of an oil on the diametral tensile strength ofconventional resin composites. In particular, two percent by weight ofeach of 10 oils (soybean, canola, sesame, olive, orange, eucalyptol,almond, safflower- vegetable and walnut) and 5 % by weight of soybeanoil was mixed with Restorative Z 100 (3M, St Paul, MN) to preparenon-metallic compositions in accordance with the present invention.

[0045] The compositions were then placed in molds to form intocylindrical specimens of height 3 mm and diameter 3 mm. The cylindricalspecimens, along with control samples of Restorative Z100, were thenirradiated with blue light of wavelength 470-480 nm and minimumintensity 450 mW/cm² for 40 seconds (Visilux 2 curing light, 3M, StPaul, MN). The specimens were compressed diametrally in an Instrontesting machine (model 4204, Intron, Canton. Massachusetts) at a rate ofcrosshead movement of 1 mm/min. The force (F) to fracture the specimenswas recorded, and diametral tensile strength (DTS) calculated from theformula:

DTS=2F/πdh,  

[0046] where h is the height of specimen and dis the diameter of thespccimen. In each case the reported data are the mean of sixdeterminations. All specimens were stored in distilled water at 37° C.for 24 hours prior to testing.

[0047] The results of this experiment are shown below in Table 1. TABLE1 Diametral Tensile Strength of Inventive Compositions Composition DTS(MPa) Control 51.4 2% soybean oil 48.9 2% canola oil 46.7 2% sesame oil53.7 2% olive oil 46.6 2% orange oil 42.2 2% eucalyptol oil 46.8 2%almond oil 53.1 2% safflower oil 48.9 2% vegetable oil 52.4 2% walnutoil 52.7 5% soybean oil 43.8

[0048] This experiment thus shows that the present inventivecompositions have diametral tensile strength values substantiallyequivalent, and in some cases superior, to conventional resincompositions.

Example 6

[0049] The following experiment was conducted to evaluate the impact ofthe inclusion of an oil on the diametral tensile strength ofconventional composites. In particular, two percent by weight of each ofsoybean oil was mixed with Vitremer (3M, St Paul, Minn.) to preparenon-metallic compositions in accordance with the present invention.

[0050] The compositions were then placed in molds to form intocylindrical specimens of height 3 mm and diameter 3 mm. The cylindricalspecimens, along with control samples of Vitremer, were then irradiatedwith blue light of wavelength 470-480 nm and minimum intensity 450mW/cm² for 40 seconds (Visilux 2 curing light, 3M, St Paul, Minn.). Thespecimens were compressed diametrally in an Instron testing machine(model 4204, Intron, Canton. Massachusetts) at a rate of crossheadmovement of 1 mm/min. The force (F) to fracture the specimens wasrecorded, and diametral tensile strength (DTS) calculated as describedabove.

[0051] The control had a DTS of 25.3 MPa, whereas the inventivecomposition had a DTS of 21.4 MPa. This examples thus shows that thenon-metallic compositions of the present invention are capable of havingdiametral tensile strength values substantially equivalent to those ofconventional compositions.

Example 7

[0052] This example was conducted to evaluate the bond strengthsattainable by the to present inventive compositions. In particular,extracted human teeth were used and each tooth was sectioned to give aportion of the tooth with an intact enamel surface. Each tooth portionwas embedded in an autopolymerizing acrylic resin cement in an aluminumring, to leave the enamel surface exposed. The surfaces were thenpolished wet under 5 lb pressure on 600 grit carborundum paper for 30seconds in an automatic polishing machine (Buehler Ecomet 3 with Automat2 powerhead, Buehler Ltd, Lake Bluff, Ill.). Each specimen was etchedwith Scotchbond etchant (3M, St Paul, Minn.) for 20 seconds, washed withdistilled water for 20 seconds, then dried thoroughly by air from apressure line.

[0053] To each surface, the control glass-ionomer (Vitremer, 3M, St.Paul, Minn.) was applied, or alternatively, Vitremer with 5% by weightof soybean oil, both of which were cured by the application of visiblelight of wavelength approximately 470 - 480 nm and intensity 450mW/square centimeter (Visilux 2 curing light, 3M, St Paul, Minn.). Thecements were used to secure stainless steel orthodontic brackets (Ormco,Glendora, Calif.) to smooth enamel. Specimens were stored in water at37° C. for 24 hours in distilled water prior to testing.

[0054] Testing was carried out using a shear bond testing rig anddescribed and illustrated by Holtan et al (Journal of Dentistry. vol 22,pages 92-96, 1994 Apr). The testing machine was Instron model 4204(Instron, Canton, Mass.) at a rate of cross head movement of 1 mm/min.Data are the mean of five determinations. Specifically, the shear bondstrength of the conventional Vitremer was 2.47 MPa while the shear bondstrength of the Vitremer with the 5% soybean oil was 2.27 MPa. These twovalues are not statistically significantly different. The relatively lowvalues are due to the nature of the tests conducted. The addition ofstainless steel brackets causes greater leverage forces to be exerted onthe bond. The relatively lower pressure of the bond was caused by gentleplacement of the bracket rather than cylinder formation approaches whichwere used in the previous examples. Also, the surface was polished verysmooth, so relatively little micromechanical adhesion occurred. Thisexample thus shows that the non-metallic compositions of the presentinvention are capable of forming bonds with strengths substantiallyequivalent to those of conventional compositions.

Example 8

[0055] This example was conducted to evaluate the bond strengthsattainable by the present inventive compositions. In particular, toothsurfaces were prepared as described above in connection with Example 7.Cylinders of either Restorative Z100 (3M, St Paul, Minn.) or ofRestorative Z 100 with 2% by weight of soybean oil and the cylinderscured by the application of visible light of wavelength approximately470 - 480 nm and intensity 450 mW/square centimeter (Visilux 2 curinglight, 3M, St Paul, Minn.). Specimens were stored in water at 37° C. for24 hours in distilled water prior to testing.

[0056] Testing was carried out as described above in connection withExample 7. Data are the mean of five determinations. Specifically, theshear bond strength of the conventional Restorative Z 100 was 21.4 MPawhile the shear bond strength of the Restorative Z 100 with the 2%soybean oil was 17.5 MPa. These two values are not statisticallysignificantly different. This example thus shows that the non-metalliccompositions of the present invention are capable of forming bonds withstrengths substantially equivalent to those of conventional resincompositions.

Example 9

[0057] This example was conducted to illustrate the impact of theinclusion of an oil on the hydrophobocity of conventional resin basedcompositions. In particular, an amount of a conventional resincomposition (Restorative Z 100, 3M, St Paul, Minn.) as well as an amountof an inventive composition (Restorative Z 100 +2% soybean oil) wereallowed to harden and the hydrophobicity of the hardened surfacemeasured by a Cahn Dynamic Contact Angle Analyzer Model DCA-322 withWin-DCA software (Cahn Instruments, Madison, WI). The conventionalcomposition was found to have a contact angle with water of 74°, whilethe inventive compositions was found to have a contact angle with waterof 84°. That is, the surface of the inventive composition was shown tobe more water repellant, less easily wettable and thus more resistant tothe deposition of bacterial plaque.

[0058] Other embodiments of this invention will be apparent to thoseskilled in the art upon consideration of this specification or frompractice of the invention disclosed herein. Various omissions,modifications, and changes to the principles and embodiments describedherein may be made by one skilled in the art without departing from thetrue scope and spirit of the invention which is indicated by thefollowing claims.

What is claimed is:
 1. A non-metallic composition for use in dentistrycomprising an essential oil in an amount effective to alter one or moreof the sensory properties, handling characteristics and hydrophobicnature of the non-metallic composition and wherein the non-metalliccomposition hardens in the mouth to form a substantially permanentfixture.
 2. The composition of claim 1, wherein the compositioncomprises a resin composite.
 3. The composition of claim 2, wherein thecomposition is selected from the group consisting of sealants ororthodontic adhesive cements.
 4. The composition of claim 1, wherein thecomposition comprises a resin-modified glass-ionomer.
 5. The compositionof claim 1, wherein the essential oil is selected from the groupconsisting of soybean oil, safflower oil, sesame oil, olive oil,sunflower oil, canola oil, walnut oil, peanut oil, orange oil,eucalyptus oil, cod liver oil, castor oil or a combination thereof. 6.The composition of claim 5, wherein the essential oil is present in thecomposition in an amount of from about 0.1 weight percent to about 10weight percent, based upon the weight of the composition without theessential oil.
 7. The composition of claim 5, wherein the essential oilis present in the composition in an amount of from about 1 weightpercent to about 5 weight percent, based upon the weight of thecomposition without the essential oil.
 8. The composition of claim 7,wherein the essential oil is present in the composition in an amount offrom about 1.5 weight percent to about 3 weight percent, based upon theweight of the composition without the essential oil.
 9. A non-metalliccomposition for use in dentistry comprising an essential oil wherein thenon-metallic composition hardens in the mouth to form a substantiallypermanent feature and wherein the essential oil is present in an amounteffective to provide the feature with a substantially hydrophobicsurface.
 10. The composition of claim 9, wherein the compositioncomprises a resin composite.
 11. The composition of claim 9, wherein theessential oil is selected from the group consisting of soybean oil,safflower oil, sesame oil, olive oil, sunflower oil, canola oil, walnutoil, peanut oil, orange oil, eucalyptus oil, cod liver oil, castor oilor a combination thereof.
 12. The composition of claim 9, wherein theessential oil is present in the composition in an amount of from about0.1 weight percent to about 10 weight percent, based upon the weight ofthe composition without the essential oil.
 13. The composition of claim12, wherein the essential oil is present in the composition in an amountof from about 1 weight percent to about 5 weight percent, based upon theweight of the composition without the essential oil.
 14. The compositionof claim 13, wherein the essential oil is present in the composition inan amount of from about 1.5 weight percent to about 3 weight percent,based upon the weight of the composition without the essential oil. 15.A method for repairing or sealing hard dental tissue comprising: (a)applying to said tissue a non-metallic composition comprising anessential oil; (b) causing said composition to harden on said tissue,and wherein the hardened composition is a substantially permanentfeature on said tissue.
 16. The method of claim 15, wherein thecomposition is caused to harden on said tissue by illuminating thecomposition with visible light.
 17. The method of claim 15, wherein thecomposition forms a bond with the tissue, and wherein the bond has abond strength of at least about 13 MPa.
 18. The method of claim 17,wherein the bond has a bond strength of from about 15 MPa to about 40MPa.
 19. The method of claim 15, wherein the composition is a resincomposite, a compomer, a resin-modified glass-ionomer or aglass-ionomer.
 20. The method of claim 19, wherein the non-metalliccomposition is a sealant.
 21. The method of claim 19, wherein thenon-metallic composition is used to fill a tooth cavity or to rebuild atooth surface.
 22. The method of claim 21, wherein the hardenedcomposition has a contact angle with water of at least about 78°. 23.The method of claim 22, wherein the hardened composition has a contactangle with water of at least about 80°.
 24. A method of adhering one ormore dental or orthodontic fixture to hard dental tissue comprising: (a)applying to said tissue a non-metallic composition comprising anessential oil, (b) placing the dental or orthodontic fixture in adhesivecontact with the composition; and (c) causing the composition to hardenon said tissue to adhere the fixture to the dental tissue in a manner soas to render the fixture a substantially permanent feature on thetissue.
 25. The method of claim 24, wherein the fixture is a dentalfixture.
 26. The method of claim 25, wherein the dental fixture is aveneer, a crown, an inlay, a crown or a bridge.
 27. The method of claim24, wherein the fixture is an orthodontic fixture.
 28. The method ofclaim 27, wherein the orthodontic fixture is a ceramic bracket or ametal bracket.
 29. The method of claim 24, wherein the composition formsa bond between the tissue and the fixture, and wherein the bond has abond strength of at least about 13 MPa.
 30. The method of claim 29,wherein the bond has a bond strength of from about 15 NIPa to about 40MPa.